Identification of transcription factors coupling the cell cycle machinery with environmental and developmental signals

In the recent years many studies contributed to our understanding of the mechanisms that drives the cell cycle machinery. Studies performed in yeast, animals, worms, flies and plants revealed that despite the evolutionary distance between these species, an universal picture can be drawn on how the basic cell cycle machinery is regulated. However, in spite of their highly conserved cell cycle machinery, it is remarkable how plants and animals have integrated the control of cell cycle differently into their specific developmental programs. In contrast to animals, plants develop mostly post-embryonic, which is characterized by continuous growth and organ formation during their entire life-span. This developmental style relies on the existence of stem cell niches within the root and shoot apical meristems, continuously supplying new cells. Next to this, plants are able to form organs de novo, like lateral roots, requiring cell cycle reactivation within already differentiated cells. Additionally, besides cell proliferation, endoreduplication plays as well an important role during different developmental processes. The plant body shows an amazing flexibility rendering them the ability to cope with different environmental and developmental signals. However, although different reports describe the influence of different environmental and developmental cues on cell cycle progression and endoreduplication, we have currently only limited knowledge on how these signals connect to the core cell cycle machinery. The aim of this project was to gain insight in how these intrinsic and extrinsic signals are integrated with the regulation of the cell cycle machinery. Although different core cell cycle genes display developmental and cell cycle-phase dependent transcriptional regulation, it is intriguing how little is known on their transcriptional regulators. Therefore the work was focused on determining new transcriptional regulators of core cell cycle genes and to try to connect these with specific environmental or developmental processes.